<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <div>Header</div>

    <div id="app">dafdasf</div>

    <div>Footer</div>

    <!-- 添加React的依赖 -->
    <script src="https://unpkg.com/react@16/umd/react.development.js" crossorigin></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js" crossorigin></script>
    <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>

    <!-- 开始开发 -->
    <!-- 注意事项: 使用jsx, 并且希望script中的jsx的代码被解析, 必须在script标签中添加一个属性  -->
    <script type="text/babel">
        // <h2></h2>: jsx代码
        let message = "Hello World";
        ReactDOM.render(<h2>{message}</h2>, document.getElementById("app"))
    </script>

</body>

</html>